Lean has been widely discussed and introduced in Sweden as well as internationally. This thesis deals with the question of how Lean has been translated from idea into practice in healthcare. It contributes to Scandinavian institutional theory, more specifically translation theory. The thesis shows how Lean is translated at the micro level, i.e. at two healthcare units that deal directly with patients. Lean is quite a broad and flexible management idea. In this thesis Lean has been specified into the central concepts of value and flow. The thesis focuses on how these concepts have been translated in healthcare, investigating the role of translators and arenas in local translation processes at the micro level. The thesis is based on a comparative case study of two healthcare units, at two different hospitals, within public healthcare. In 2009 the healthcare units started to implement Lean with the aim that they would improve patient flow and increase quality. The thesis includes a vast number of internal documents, interviews and observations. It also includes a follow-up of the two cases a few years after the initial interviews were carried out. The study presents a number of contributions. Analysis shows that the local translation process in each case resulted in a mutual adaptation between Lean and practice. Furthermore, the introduction of Lean didn´t change the work of the units completely. Lean was translated in a way that supported how the units were organized already before the introduction of Lean instead of changing them. The analysis also shows that the translation of Lean was not isolated within the healthcare units, but spilled over into and was influenced by the surrounding context, both to the private sphere and to other organizations. The findings indicate that translation is something that is going on everywhere, all the time and that the connection between the public and the private sphere, through conversations and small talk about Lean, can be a way of spreading and translating ideas. The introduction of Lean at the units started as a top-down process. But Lean was also translated horizontally to and from friends and family members who had met Lean in other contexts. The translators and arenas at the micro-level filled an important function in the way in which Lean was translated into practice in the operational core where small talk and discussions seemed to be important. But in addition to this the thesis also shows that an actor in a formal position is required to add energy and drive the work with Lean forward.